The present invention relates to testing of multiple signal transceivers, and in particular, to automated testing of multiple data packet signal transceiver devices under test (DUTs) using shared testing resources.
Many of today's electronic devices use wireless signal technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless signal technologies must adhere to various wireless signal technology standard specifications.
When designing such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless signal technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless signal technology standard-based specifications.
For testing these devices following their manufacture and assembly, current wireless device test systems typically employ testing subsystems for providing test signals to each device under test (DUT) and analyzing signals received from each DUT. Some subsystems (often referred to as “testers”) include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the DUT, and a vector signal analyzer (VSA) for analyzing signals produced by the DUT. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable (e.g., through use of an internal programmable controller or an external programmable controller such as a personal computer) so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless signal technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
As part of the manufacturing of wireless communication devices, one significant component of production cost is costs associated with these manufacturing tests. Typically, there is a direct correlation between the cost of test and the sophistication of the test equipment required to perform the test. Thus, innovations that can preserve test accuracy while minimizing equipment costs (e.g., increasing costs due to increasing sophistication of necessary test equipment, or testers) are important and can provide significant costs savings, particularly in view of the large numbers of such devices being manufactured and tested.
Another critical factor in test costs is that of test times, and more particularly per-device test times, which must be minimized without compromising test integrity. Overall test times are determined by actual DUT testing activities (e.g., testing DUT performance in accordance with underlying system and DUT standards), DUT handling activities (e.g., connecting, disconnecting, moving of DUTs), and test preparation activities (e.g., initializing and/or synchronizing DUTs with the test system). Once test times have been optimally reduced for a single device, a next advance in reducing test time and cost involves testing multiple DUTs in a pipeline (e.g., overlapping sequences of distributed testing) or in parallel (e.g., concurrent testing of multiple DUTs) testing. This can include assembling and connecting one or more testers with additional signal routing circuitry (e.g., signal dividers, combiners, switches, multiplexors, etc.) as needed for providing receive (RX) signals to the DUTs and for receiving and analyzing transmit (TX) signals produced by the DUTs.
Where multiple DUTs are tested while sharing tester resources, worst-case estimates of time juxtapositions are typically used when programming the tester to share those resources so as to ensure no contention among the DUTs. Some DUTs will complete test steps sooner than others, in which case they become idle while awaiting programmed access to tester resources. In terms of test time, this is wasted time and increases test time and cost.
Accordingly, it would be desirable to have a dynamic access control where access to tester resources is optimized based on real-time states of the multiple DUTs and the distributed test or parallel-test priorities of the current testing circumstances. Dynamic management of tester resources, where access is determined by an overarching optimization effort, would allow multiple devices to be tested during the same overall time interval and thereby make optimum use of tester resource while reducing time and cost.